The invention applies generally to overhead garage doors operated by motorized means which are usually controlled remotely, for example by a small, battery-powered, coded radio transmitter and a responsive decoding receiver associated with a motorized door operator. That arrangement is known and in fact, is in wide use for slab type doors and multi-panel doors. The slab type door is generally a lower cost arrangement vis-a-vis the multi-panel door. The former swings up and down about a fulcrum associated with the mechanical suspension mechanism mounted at both sides of the slab door and garage door opening, whereas the latter travels substantially vertically over the door opening and folds progressively such that the panels are all substantially in a horizontal plane in the door open condition.
The prior art known to the applicant includes a number of U.S. patents relating to side hinged garage type doors or gates of the single or double, swinging type. Examples of such prior art include U.S. Pat. Nos. 913,269; 1,725,846; 1,831,117; 1,949,133; 2,039,296; 2,131,415 and 3,617,080.
In U.S. Pat. No. 913,269 a very early form of manually operated bolt (latch) mechanism on a swinging door is disclosed.
In U.S. Pat. No. 1,725,846 another early swinging door latch device is shown using a manually operated trigger for to effect very rapid door opening, as for example required of the doors of a fire engine house.
U.S. Pat. No. 1,831,117 describes a garage swinging door opening mechanism activated by contact with the bumper of a vehicle preparing to enter the garage.
U.S. Pat. No. 1,949,133 discloses another vehicle activated garage door opener, in that instance responsive to the weight of a vehicle or a "depressible platform" in the driveway surface approaching the garage.
In U.S. Pat. No. 2,039,296, a basic manually operated multiple-panel overhead door is shown. That arrangement could be modified to include the unique self-locking and unlocking structure according to the invention, as will be understood from the description hereafter presented.
U.S. Pat. No. 2,131,415 discloses a slab type overhead garage door with separately operated hydraulic actuation (actually using water as a hydraulic fluid).
U.S. Pat. No. 3,617,080 describes a door latch mechanism for swinging or sliding doors but is not adapted to overhead doors of the slab or multiple panel types.
U.S. Pat. No. 2,074,347 relates to a slab-type overhead door, which is a type of door to which the combination according to the invention is particularly adapted if the motorized and remotely controlled opening and closing apparatus, which is now well known, were also added.
The well known overhead slab door arrangement includes a spring counter-balanced suspension at each lateral position whereby the door is rotated as a unit about a fulcrum associated with the door frame structure. When fully closed the door is in a substantially vertical plane and when fully open it is in a substantially horizontal overhead plane. The spring counterbalance is so arranged that, in closing, the last fraction of the travel to the fully closed position is nearly a free fall, i.e. is not substantially resisted by the spring counterbalancing action. Thus the door tends to stay closed until an intentional opening force is applied.
Upon opening, the slab type overhead door bottom edge typically follows a somewhat irregular arc outward and upward with contemporaneous translation inward with respect to the garage door opening such that the amount of horizontal plane projection outside the garage opening is minimal. The manner in which the well-known characteristics of such a suspension mechanism together with the typical motorized and remotely controlled opening-closing mechanism are employed to advantage in cooperation with the novel structure of the invention will be understood as this description proceeds
The well-known garage door opener is not particularly secure against intruders. The door operated by the usual opener/closer is subject to prying from the bottom, usually with damage to the mechanism. Accordingly, there is a great need for simple reliable and inexpensive auxiliary locking means. The provision of such means according to the invention will be appreciated as this specification proceeds
Although not described in the patent literature aforementioned, it is known that electric solenoid operated locking both arrangements have been constructed and offered for sale. Those devices operate in conjunction with the typical motorized garage door operator to produce locking of the door the closed position. Such arrangements are relatively expensive however.